I am new to Ubuntu so, I thought to give a try. Using rufus I created a bootable drive for ubuntu. My plan to boot the ubuntu from USB stick but mistakenly I installed in the OS in the C drive which format my existing windows 10 OS.
I bought this laptop 5 years ago with OEM license. Now my OS + all of my files has gone. Now what should I do to recover files and OS?
Sorry for your loss. Do you have any backup for your data? and What do you mean by all of my files have gone? didn’t you had files in the separated partitions like D or E drives?
For OEM license have you used Microsoft account login to your laptop? If yes then your device and license key must have fetched to your account. Login to your Microsoft account in any browser and check you can see the device configuration there. If you see the device details then you are safe in this case you do not need to worry about the license. You can just fresh install the Windows 10 OS and login with the Microsoft account you have Windows will automatically activate the license in a minute.